Motor fan blade control



Y E N O O M E MOTOR FAN BLADE CONTROL Filed June ,6, 1945 Patented Apr. 27, 1948 UNITED STATES PATENT OFFICE MOTOR FAN BLADE CONTROL Edward Mooney, Venice, Calif.

Application-lune 6, 1945, Serial No. 597,860 2 Claims. (01. 230-270) My invention relates more particularly to new and useful improvements in thermostatically controlled fan blades for internal combustion engines, whereby the cooling function will be applied as needed and greater efliciency result from the operation of the motor.

It is well known that these cooling fans run at great speed and that the centrifugal force thereon is considerable and that there must be means for preventing outward movement of the fans with a resultant turning thereof, and that the means for changing the angle of the fan blades must be free to move them by change of temperature, and not incidental or accidental.

Among the salient objects of my invention are: to provide in a fan blade a series of blades rotatably mounted in their support, with threadiike connections therein which will permit the fan to turn on its axis but will prevent any slid- 1 ing movement outwardly longitudinally thereof;

to provide in connection therewith thermostatically actuated means connected with the inner ends of said fan blade mountings for turning them in response to change of temperature, whereby the angle of said fan blades will be changed to give more or less cooling action, as

may be required; to provide a mechanism of the character referred to which can be readily attached to present fan-driving drums or pulleys, whereby to make possible my improved fan blade control which can be readily adapted to present motors: and, in general, to provide a simple, practical and emcient motor fan blade control which will function automatically to control the temperature of the motor on which it is used.

In order to fully explain my invention, I have illustrated one practical embodiment thereof on the accompanying sheet of drawings which I will now describe:

Figure 1 is a. front elevation of a motor fan embodying my invention;

Figure 2 is an enlarged view of the hub portion thereof, with the cover removed and with the fan blades broken away to reduce the size of the view;

Figure 3 is an enlarged vertical sectional view through the mechanism, taken on the line 3-3, of Fig. 2;

Figure 4 is a cross sectional view taken on the line 4-4 of Fig. 2; and Fig. 5 is an edge elevation of an operating member adapted to fit over the thermostat element for connection with the 311181 ends of the fan blade shafts for turning Referring now in detail to the drawings, I

will describe this particular embodiment of my invention used for illustrative purposes. The body of the device is of cup shape, designated 6, with the radial bearing arms I, 1, bored and threaded to receive the shafts 8 of the fan blades 9, with threaded connection within said arms, as at 1', whereby said fan blade shafts and fan blades can turn within said arms and at the same time cannot be thrown outwardly by centrifugal force under great speed. It will also be understood that this makes for ease of asset bling the fan blades and their shafts into and through the body arms I, l. The inner ends of said fan blade shafts 8 are provided with small coiled springs, as Ill, set for automatically turning them to a straight edgewise position, all in the same plane, under normal temperature when cooling is not desired, or when the fan is at rest. Set in the end of each of said fan shafts 8, is a laterally projecting finger, as II, over which one end of the small coiled spring Ill, rests inorder to function in turning the fan shaft, the other end of said spring resting on the bottom of the body, as will be clear from Fig. 2.

Mounted in the body cup 6, is a thermostat element, sometimes referred to as a. Sylphontype of thermostat, and here designated I2, and

which is designed to expand and contract axially moves said operating member I3 and its fingers I4 outwardly, and thereby moves the fingers II, II, on the inner ends of the fan shafts, thus changing the angle or pitch of the fan blade of each, all in unison and uniformly, and holding them in the adjusted position.

In the embodiment of the invention here shown, I have indicated how it can be applied or afilxed to the pulley drum I5 by means of through bolts l6, I6, with the motor shaft ll, at its outer end resting within the thermostat element It. Said bolts It also secure a cover I 8 over the open cup-like body 6, the end of the motor shaft I'l being provided with flange-like clamping elements, as I'I' whereby the pulley 3 drum iliselampedsecurelytothebodylof the embodiment cf'the invention here shown.

I have also shown said cover member ll provided with an adjustable stop or limit screw II, with lock nut 20 thereon for holding it in adjusted positions. This can be set to form a limit stop for the axial expansion of the thermostat element I: in places where such is needed or can function to advantage.

The advantages of automatically adjusting the fan blades according to the requirements will be evident to those versed in the art. Under present conditions the fan is driven at full speed even when the motor is cold with that waste of power and in the desert where a greater cooling action is desirable, the output is the same as where the weather is cold.

I do not limit my invention to the details of construction here used for explanatory purposes, knowing that changes can be made without departing from the spirit of the invention, except as I may be limited by the hereto appended claims forming a part of this specification.

I claim:

1. An air circulating fan structure including a cup-like body having radially extending hearing arms bored and threaded with low pitch threads,

a fan blade with shaft correspondingly threaded for each of said arms, the ends of said shafts extending into said cup-like body and provided with coiled springs and laterally extending fingers, a thermostat mounted axially in said cup-like 4 gnarl! fan blade to cbanso the pitch of the fan 2. A cooling fan of the character shown and described including a cup-like body with means for mounting it on a drive shaft, said shaft being hollow for flow of hot air therethrough, a thermostat mounted axially on the end of said shaft within said cup-like body, said thermostat having a member thereon with projecting fingers, said 10 body having radially extending arm portions body, said thermostat having thereon laterally extending fingers positioned to engage crosswise the fingers on said shafts, whereby each finger projecting from said thermostat engages a finger ing such that centrifugal force cannot cause any 9 2,284,938

turning of said shaft and fan blade, said thermo- 1 stat operating to automatically turn said shaft bored and threaded with low pitch threads therein. a fan made with a shaft for each of said arms, said shafts being threaded with corresponding low pitch threads to mesh with said threads in said arms, whereby said shafts and blades can be turned mechanically in said arms but cannot be turned by centrifugal force under high speed,

lateral fingers projecting from the inner ends of said shafts in crossed relationship with the fingers on said thermostat, whereby expansion of said assurances crrnn The following references are of record in the file of this patent:

UNITED STATES r a'rnu'rs Number Name Date 1,449,605 Luther et al. Mar. 27, 1923 1,787,041 Hughes Dec, 30, 1930 1,980,249 Bates -1 Nov, 13, 1934 2,118,654 Meijer May 24, 1938 2,160,745 Levy ..'May 30, 1939 2,225,209 Dewey Dec. 17, 1940 Allen, Jr. June 2, 1942 2,916,940 Dewey et a1. Apr, 20, 1943 

